I'm not sure Ken Holman will celebrate, given that the transformation
layer lately is mostly amalgams of _javascript_. It does seem like yes,
though, transformation is rapidly becoming more important as the tasks
people perform on the Web become more complex.

"Fifteen years ago, arguing with people cheering on XSL transformations, I
argued that decoration, CSS style, was enough. The virtues of its relative
simplicity vastly overwhelmed the extra things XSLT made possible.
Reordering the document tree might be a nice idea, but in 1999 the
document tree was mostly made on the server in response to client
requests.

Even today, XSLT remains a steep climb for most web developers.
Client-side XSLT never found widespread support (though Saxon-CE and
Frameless are well worth exploring). XSLT remains alien to most web
developers.

Instead, we keep reinventing transformation with more familiar tools,
often _javascript_ tools. Few of these tools aim for the completeness or
complexity of XSLT. Unfortunately, though, these tools are fragmented
across many different communities (for frameworks) and people building
their own versions.

Stepping back from the infinite details of frameworks and toolkits, some
patterns begin to emerge..."